Thursday, July 18, 2013





Before this summer I really had no idea what physics was. Now I think I know what physics is. Physics is motion, sound, and light. Physics plays a role in almost every minute of everyones lives. Physics is everywhere. Its the study of nature, matter and energy, which pretty much is everything that surrounds us.

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I thought this class was awesome! At first I wasn't excited to be in a class that was six weeks long, and six hours long two days a week, but this class went by so quickly. This class wasn't like a normal class where you sit in your seat all day and listen to a teacher drone on, this class was interesting. We did a lab almost every day to keep things interesting, and we did some pretty fun stuff. I like how the atmosphere was fun and comfortable. I felt like I learned a great deal and was always allowed to ask questions if I was confused.

This summer boy oh boy did we learn a bunch ! First unit we learned about metric conversions and scientific notations which are crucial things that we will probably need in any science class. We also learned about different types of graphs no relationship graphs, linear graphs, inverse graphs, square graphs and squared graphs. All of these graphs will be helpful in the future whenever I am doing work involving graphs. We also learned about accuracy and precision. In the second unit we did a lot of kinematics and I learned about scalars, vectors, and velocity. I learned all of the graphing rules for position vs. times and velocity vs. time graphs. In unit 3 we learned all about acceleration How to get acceleration and how to graph it. We also learned about DATVVo questions and DAT, VAT, & VAD Unit 3 was one big math lesson. Unit 4 was similar to unit 3 it had a lot of math except the problems had to do with projectiles. The major thing we learned is that axes are independent, what happens on the x or y axis stays on the x or y axis. Unit 5 was all about vectors and trig. We learned about Bureku and different forces. We had to know how to diagrams too. We learned about all of newtons laws, law of inertia, law of acceleration and action reaction. This unit had a lot to do with forces and we learned about friction. Unit 6 was similar to unit 5 it involved diagrams. We learned the equation Fnet=ma and about friction. There are two different types of friction static and kinetic. In unit 7 we learned about momentum. We learned about momentum is always conserved and that p=mv. We also learned that objects with momentum will stay with momentum unless acted on by a outside unbalanced force. Elastic is bouncy, in elastic sticks. Unit 8 was a big one. We learned about work, energy and power. Energy is conserved like matter and momentum. Energy is a scalar and there are three different types of energy. There is kinetic, potential gravitational, and spring potential. We also learned equations to get all of these energies. Work = change in energy, force x distance. Power = work divided by time. Unit 9 was about waves, mostly sound waves. We learned about the characteristics of a wave like the wave length, the crest, trough amplitude. We also learned about medium which is the material a wave is in. Period and frequency have to do with the time of a wave. We learned about transverse waves and longitudinal waves. An example of a transverse wave is light and a example of a longitudinal wave is sound. We learned about constructive and destructive interference which has to do with two waves in the same area. Reflection is bouncing and refraction is bending, which we focused more on in the next lesson. Unit ten was a big one. We focused on light and its reflection and refraction. Light is an electromagnetic wave meaning it needs no medium. The two different types of reflection are specular and diffuse. Specular reflection is on smooth surfaces and diffuse is on rough and bump surfaces. We learned about light too, the primary and complimentary colors and how they are different from pigments. We also answered important questions that had to do with light and color like why the sky is blue and why the ocean is blue. The law of reflection states that the angle of incidence= the angle of reflection this was crucial when we were drawing ray diagrams. We also learned snails law which has to do with fast and slow mediums. Depending if the light goes from a fast medium to a slow medium or a slow medium to a fast medium the light will bend towards the normal or away from. Every material has a different index of refraction like water has 1.33 and glass has 1.5. Lastly we learned about drawing light rays in lenses and how to tell if the image was real or virtual, inverted or upright and enlarged or reduced. We figured those things out by drawing parallel rays, focal rays and essential rays,

I liked how this class was really fun. We did so many activities every day, I was never really bored. Mr. Blake always found a way to make the class interesting. Some really fun activities we did were the slip n slide, the bottle rockets, the human pendulums. Labs that I enjoyed were the projectiles one, and all of the light demos and the light lab were really fun too. I liked how we were emailed our grades frequently so that we always knew what our grade was, and didn't have to ask or never know. I have never been in a class where we are emailed our grades and it was a nice change. I also liked the unit packets that we got every unit. They were really informative and had a great unit review at the end. They were good for studying with before any test. I also like how we didn't have a text book like most other classes, just our notes and the worksheets we got. Another thing that I liked was the unit quizzes that were online. They were a good review of things we learned and I used them before every test to study. I liked how our only homework every day was a simple blogpost. The blogpost is a good idea because it is pretty simple but its also a  good and creative way to review over what we learned. I liked how Mr. Blake always wrote our agenda for the day on the board, it was nice to know what we would be doing for the day.

One thing that can be modified is the lack of field trips we took. We did take "field trips" trips to the field but I think that one or two field trips in this course would be a good idea. We could go to the water park to learn about waves or anywhere really because physics is everywhere.

Mr. Blake thanks for being such a great teacher! Even though your from Kamehameha you were still good. You also made class enjoyable to be in with your music and jokes. I also felt like I knew what was happening in class because you were good at repeating information and explaining it well. I had a great summer thanks !

Wednesday, July 17, 2013

Unit 10 - Light Properties (Refraction)

This is a simpler example of some of the stuff we did in class today. Mr. Blake had a laser like in this picture and put glass objects in front of it, with the lights off we could see how the light refracted when it had to travel through the glass. In this picture the light goes through glass and the water, maybe if I had held the laser a little farther away you would of been able to see how the light refracted

In class today we learned SO much! We continued our learning on unit 10 light properties but today we learned about refraction. The main concept that we learned today is snails law. Snells law states that when moving from a fast medium to a slower medium, light will bend towards the normal. It also states that when moving from slow to fast (medium) light will bend away from the normal. This concept was major when we looked at lots of problems involving mirrors, light sources, glass, water, and air. In these problems we had to draw diagrams and snails law was important for all of them. Snells law was important for these diagrams because by knowing the materials that the light went through you could figure out if the light is going from slow to fast or fast to slow, then you could figure out which way the light refracted or would bend. For these problems we also used the equation:
(n1)(sinangle1=(n2)(sinangle2). Critical angle is when n1 > n2 and when the light goes from slow to fast.  Total internal reflection is when the angle of incidence > critical angle.

N is the index of refraction, the ratio is n= c/v where c is the speed of light in a vacuum and v is the speed of light in the medium. Every material has a different index of refraction. For example water and ice have different index of refractions, air and air have the same index of refractions. N of a vacuum=1 , N of air= approx 1, n of water =1.33, n of glass is 1.5, and n of diamond = 2.42. Index of refraction don't have units.

We also learned about different types of rays. Parallel ray is from the object parallel to the optic axis through lens and bend through the focal point on the other side. Focal ray is from the object through the focal point on the object side through lens then parallel. Essential ray goes from the object through the center of lens then continue (no bending). You need to use all three of these rays when you are drawing ray diagrams with lens. For these diagrams you need to state it's characteristics like if its real or virtual, upright or inverted, and if its enlarged or reduced. You can tell if the image is real or virtual by if the rays are converging or spreading apart.

Tuesday, July 16, 2013

Unit 10 - Light Properties (Reflection)


Today we learned a whole bunch! All of what we learned was about light and we focused on reflection. We did a lot of cool demos in class today involving colors of lights. Light colors are different from pigments, like paint. When light colors interact they don't combine to form colors like pigments do. For example when a yellow light hits a blue screen the resulting color is black, for pigments when yellow and blue are added together the resulting color is green, see the difference?

Here is a picture of the colors we learned about. The big circle colors red, blue and green are primary colors, the small colors magenta, yellow and cyan are the complimentary colors. When you add red, blue and green together you get white.


 Today we played around with color for a while. We had 3 projectors with the colors red, blue and green. 2 of the projectors would go on and then we would see what the resulting color would be. Then we would look at a worksheet that had problems like what color would be produced when yellow was shone onto a yellow screen. The answer would be yellow. It all has to do with reflection and absorption 

We learned that there are two types of reflections specular and diffuse. Specular reflection is when a surface is relatively smooth compared to the wavelength of the wave (reflection comes off as it is) . Diffuse reflection is when the surface of an object is bumpy or rough when compared to the wavelength of the wave, ex. light.

 White light is light that has all the frequencies ROYGBIV. White reflects while black absorbs. Shadows are places with an absence of light. The big idea that we learned today is the idea that you can only see light if it is reflected to your eyeballs. 



We learned about things about the earth that I have always wondered about like why the sky is blue and why the ocean is blue. The sky is blue because scattering of the blue wavelengths in the upper atmosphere due to nitrogen. The ocean is blue because water absorbs lower frequency lights. Absorbs ROY and then GBIV is left. Rainbows are because of dispersion. Light bends inside of a raindrop and rainbows are always opposite the sun.


The law of reflection is that the angle of incidence equals the angle of reflection; all angles are relative to the normal. The normal is perpendicular to the surface. Object distance= do= distance from object to mirror /lens. Object height= ho= height of object.  Image distance= di=distance of image to mirror/lens. Image height=hi=height of image. Another thing we learned is that unless there is fog in the air it is not possible to see a beam of light from the source because it is now directly going to your eyes.





Monday, July 15, 2013

Unit 10 Light


 Today we learned about LIGHT, this is why I have a picture of lamp because lamps making light. We learned a lot of terms today. Two important terms we learned are opaque and transparent. Opaque means not letting through, transparent means can go through. The velocity of light = C= 3 x10 ^8 m/s. The velocity of light is faster in space because there is no medium in space, on earth it is a little slower. Sound is a pressure wave meaning it needs a medium. Light is an electromagnetic wave meaning it needs no medium. Light travels faster than sound.
A light year is the distance light travels in one year. Light is a transverse wave and it has electricity and magnitude. We learned all about the different ranges of frequencies today too. Ranging from radio and tv waves to microwaves to uv radiation to x rays to gamma rays. We also learned about light reflectors, an example of this are books, which don't actually provide light, but reflect it. Things like flashlights or lamps or laptops are not light reflectors. Shadows are places with no light.

Saturday, July 13, 2013

Unit 9 Waves and Sound



My picture is of Beats headphones because headphones represent sound and we learned about sound yesterday. We first learned a lot of terms: 
Reflection is the bounding of waves an example is echoes. Refraction is the bending of waves due to changes in wave medium an example is waves at a beach. Dispersion is the spreading out of waves. A standing wave is a wave that looks like its not moving. Natural (resonant) frequencies are the frequencies that an object wants to vibrate at specific depends on physical qualities of an object. Resonance is the increase in amplitude of a system exposed to a force at an objects natural frequency. Ex. a glass shattering after rubbing the top/ vibration, kidney stones and a twisty bridge. Sound itself is a longitudinal wave and needs a medium to travel through. Sound travels fasted in solids, then liquids then gases. Pitch is the frequency of the sound. All frequencies of sound travel at the same speed and temperature, but do not travel at the same medium. 

Yesterday we completed a lab involving a tuning fork. We would hit 5 different tuning forks with different frequencies against our shoe or a harder object, resulting in the tuning fork making a noise. Then we would hold it to a tube that was in a cylinder of water and pull the tube up with the tuning fork until the tuning fork make a loud noise. We would record down the length of the tube from the water then calculate wavelength (x4 the length) and the wave speed (the wave length x the frequency). 

Thursday, July 11, 2013

Unit 9

This picture shows what we learned in class today. Today we learned all about waves today. 
A represents crest or the highest
B represents trough or the bottom 
C represents the amplitude or the distance from the crest or the trough to the equilibrium 
D represents a loop 
E represents a wave 
F represents the nodes which are places between the loops with no movement
The orange parts represent the equilibrium 

Waves are ways of transmitting energy 
Vibration is "wiggle" in time.
Medium is the material that the wave is in. Some waves need a medium to go through. 
Wave length is the length of a wave, it can be measured from two identical portions of the wave. Ex. Crest to crest. 

We also learned about different kinds of waves. There are two types, transverse and longitudinal. Transverse waves are waves that have energy that moves perpendicular to wave velocity. Ex. light Longitudinal waves are waves that have energy that moves parallel to wave velocity. Ex. sound. Period is the time it take for one cycle to occur. Frequency is how many cycles go by in a second, the units for frequency are hertz or 1/ seconds. There are three important equations that we learned: 

Period= 1/ frequency    Frequence = 1/ Period    Wave velocity= frequency x wave length 

We learned a bunch of other terms like the principle of superposition which is when two or more waves are moving through the same space. Depending on direction waves can have a positive sign or a negative sign. If two positive waves or two negative waves collide they have a constructive interference and join together to create a large wave. If one big positive wave collides with a small negative wave they have a destructive interference and will result in a smaller wave. If a positive wave and a negative wave of the same size collide they can result in a flat wave. Nodes are areas of no movement, antinodes are places where there is the most movement. 


Wednesday, July 10, 2013

Water Bottle Rockets 7/10 !

Our water bottle rocket included:

One two liter soda bottle
4 triangle shaped 5 by 1.5 inch fins-
A big funnel that we used as our cone
A ball of clay inside the funnel
A piece of saran wrap to cover the clay
A circle shaped parachute made out of a garbage bag
Four long strings attaching the parachute to the rocket
A lot of duct tape

We got our design from instinct and the internet. The internet told us to make triangle shaped fins, but we chose the size of them. We chose poster board for our fin material because we knew it was sturdy and light. Matt brought in the funnel so we used it. We used a ball of clay because a website told us that clay was a good mass to use and it would stay well in the cone. We at first used a glass circle to cover the clay so the parachute wouldn't stick to it, but it didn't work well so we got a piece of saran wrap and covered the clay so it wouldn't stick to the clay. We used a garbage bag because we thought it would be sturdy and a good size. We cut it into a circle because a website told us to, and we knew that a wider parachute was best. At first we had short strings attaching the parachute to the rocket but Mr. Blake told us to change to longer strings when our parachute failed to do well. We used duct tape because duct tape is the strongest tape.

What worked as planned was the clay, the shape and size of our bottle, and our fins. All these things worked well, and we didn't have trouble with. What didn't work as well was the parachute, the cone, and the strings. The parachute didn't come out more than half of the time. Our small cone broke on our 5th trial because it fell downward and cracked when it hit the ground, good thing we had a bigger cone as a backup. This bigger cone ended up working out much better. It was bigger so that the parachute could fit and open up when in the air. The short strings didn't work yesterday so we got longer strings. The longer strings always got tangled though and on our 16 second trial they got twisted as the rocket was falling down.




PSI: 80
Amount of water: About a liter
Times:
5.59 s
6.71 s
11.87 s
Avg: 8.06 s
8.1 s
5.1 s
6.79 s
9.4 s
5.4 s
16.7 s
Avg: 8.58 s


Project taught us: 



This project taught me that a light mass is better. Our water bottle rocket was pretty light and so it went up higher, lots of other rockets were heavier so they didn't go up as high. This shows us physics because more mass means more inertia. The heavier rockets wanted to stay down so they didn't go up as high.
Also on the first day we filled our rocket up with 1/3 of water, which was not as successful. On the second day we filled it up with 1/2 of water which resulted in a higher rocket.
For your rocket to go high you also need a high PSI too, more pressure means a higher rocket.
We learned from this project that wider and bigger parachutes were also better. This is because they catch more air and result in a longer falling time.
The cones of our rockets couldn't be too secure on the rocket because as the rocket is going up friction is pushing down super hard on the rocket and for the parachute to work the cone needed to fall off, so you had to be sure your cone was loose.
 Longer strings were better because it allowed the parachute to take on more air. Some groups had paper cones, we had a plastic one and ours was more successful because it was stronger against the wind and didn't crush when it fell.




I'm happy with the time of our rocket. All our low times were because our parachute failed to come out, but when we changed to a higher cone, the parachute came out easily. It was really scary watching the rocket fall because the parachute would always only come out at the end about 15-18 ft above the ground. When the parachute came out though it dropped really slowly resulting in a slow time.